Jig washer



Feb. 22, 1966 M. BosMAN JIG WASHER Filed Nov. 24, 1961 Mah ma/,M @www 6)/ WLM 99ml?? Mw United States Patent Olice 3,236,382 Patented Feb. 22, 1966 3,236,382 HG WASHER Machiel Bosman, Beek, Netherlands, assigner to Stamicarbon N V., Heerlen, Netherlands Filed Nov. 24, 1961, Ser. No. 154,694 Claims priority, application Netherlands, Nov. 26, 1960, 258,455 Claims. (Cl. 209-457) The present invention relates to jig washers for separating particles of different specific gravity and has particular reference to a new and improved means for controlling the quantity of the material discharged from an extraction chamber therein. A jig washer extraction chamber of this character is always filled with heavy material which has been separated. The resistance of this material is so strong that the pulsations of the separator liquid are practically imperceptable at the point where the separated heavy materials leave the screen, thereby promoting the accuracy of the separation. Such installations enjoy the further advantage that the use of an overliow Weir between two adjacent jig lcompartments is no longer necessary.

In known jig constructions of this character, an adjustable plate is attached to the wall of the installation chamber opposite to the fixed plate so that the larger percentage of the weight of the material in the extraction chamber rests -on this plate. In this known prior art construction, the plate slopes downwardly as a result of which the lumpy material slides from the extraction chamber by gravity, the amount of material to be discharged being -controlled by varying the slope of the plate. Necessarily, a large force is required to move the plate upwardly and there is a danger of large lumps of material becoming jammed in the outlet opening of the extraction chamber when the plate is so turned. In such a situation, the disch-arge opening cannot be reduced further in size thereby resulting in a discharge of material even when, in view of the composition of the wash bed in the jig, removal of the heavy material would be undesirable. This may cause material of lower specic gravity to become commingled with the heavy material so as to be lost.

According to the present invention, there is provided a jig washer which includes a new and improved extraction -chamber construction which obviates these shortcomings of the prior art. This invention contemplates the provision of an adjustable plate attached to the lower end of the downwardly inclined stationary plate which constitutes the bottom wall of the extraction chamber. The adjustable plate is inclined upwardly, and is outside the main portion of the extraction chamber, i.e., positioned so that the extent of the heavy material in the extraction chamber forms a natural slope on the plate. Accordingly, the adjustable plate does not take the weight of the material present in the extraction chamber so that only a small force is required for controlling the discharge of the material therein.

This invention also provides la discharge arrangement for an extraction chamber in a jig washer wherein means are provided for preventing blockage of the plate by a lump of material which has become jammed in the outlet opening of the extraction chamber. Accordingly, the extra material in the extraction chamber is discharged by the pulsations of separation liquid. These pulsations, however, do not propagate to the place where the heavy product leaves the screen of the jig washer. Further, the adjustable plate may be perforated so that the pulsations of the separatory liquid directly affect the slope of the material on the adjustable plate.

Still further according to this invention, the amount of heavy material discharged from the eje-ctor is controlled by shifting or pivoting the adjustable plate. Preferably, the adjustable plate is 'hinged at its lower end to the lixed plate of the extraction chamber so that the adjustable plate is positioned entirely outside the plane of the eX- traction chamber.

These and still further objects, advantages and novel features of the present invention will become aparent in the specification and claims, taken in connection with the accompanying drawing.

In the drawing, there is shown a jig washer 1 having top screens 2 and 2' across its upper end, the screens being disposed in spaced apart relationship. Carried by the jig washer 1 are downwardly facing air chambers 3, the drawing showing two chambers positioned below each screen 2 and 2. These chambers 3 are operable to create a pulsation of the liquid in the jig washer 1 by any suitable means. in this regard, the pulsating means disclosed in the copending application of De- Koning et al. Serial No. 155,060, led November 27, 1961 and entitled Method of and Apparatus for Separating Particles of Different Specic Gravity in a Jig is conveniently operable in the present apparatus, the teaching of this application being included herein by reference.

The top of jig 1, adjacent the screen 2, carries an inlet chute for supplying the material to be separated to the screen 2, such as raw coal. As a result of the pulsations created in the pig 1, the material is separated into a bottom fraction of high specic gravity, e.g. shale, and a top fraction of lower specific gravity, e.g., coal and middlings. Positioned at the end of the screen 2 and adjacent the screen 2 is a vertically extending extraction chamber 5 defined by opposed vertical walls 6 and 7, the wall 6 being connected to the end of the screen 2. The wall 7 of the chamber 5 divides the jig 1 into two compartments, 8 and 9, which compartments are bounded at their upper ends by the screens 2 and 2. The wall '7 extends upwardly beyond the screens 2 and 2 so that the fraction of high speciiic gravity collects in the chamber 5 while the lighter fraction is washed over the upper edge of the wall 7 into the second compartment 9 and screen 2'.

Joined to the bottom of the end walls 7 is a lixed plate 10 which is inclined downwardly and extends substantially to the plane of the opposite wall 6 of the chamber 5. Thus, a separation between the bottom edge of the wall 6 and the lower free end of the stationary inclined plate 1h delines an opening 11 in the chamber 5. An adjustable discharge plate 13 is hinged at its lower end to the bottom free end of the plate 10 at 12. This plate 13 is upwardly inclined so that the heavy fraction, such as shale, llowing from the opening 11 of the extraction chamber forms la natural slope 14.

As will be appreciated, the weight of the heavy fraction in the extraction chamber is supported primarily by the plate 10. The plate 13 is of suicient length to prevent the shale from owing from the extraction chamber 5 of its own accord. Each pulsation of the liquid in the jig washer causes the shale forming the slope 14 to be slightly lifted, the resulting free space being filled by shale, which gravitates down the extraction chamber 5. Accordingly, after a heavy pulsation, shale will pass across the upper edge of the plate 13 into the jig washer 1 below the screen 2, where the material settles and is discharged by a bucket elevator 15 at the bottom of the jig washer 1.

Advantageously, the shale on the plate 13 can be pulsated more effectively by providing this plate 13 with perforations. The extraction chamber 5, of course, receives practically no pulsations and this prevents shale which is present over the entrance of the extraction chamber from being washed over the upper end of the wall 7 into the compartment 9 on the upward pulsating stroke,

and further prevents components of low specific gravity from being sucked into the extraction chamber on the downward pulsating stroke.

The quantity of shale discharged by the pulsating stroke is controlled by adjusting the inclination of the plate 13 relative to the horizontal. When the angle between this plate 13 and the horizontal is decreased, more shale is obviously discharged and conversely, when the angle is increased, there is a decrease of shale which is discharged.

In view of the fact the wid-th of the discharge opening 11 is unaffected by such a change, heavy products cannot become jammed in the discharge opening. The control of the angular position of the plate 13 is carried out by a float 16 which scan-s the thickness of the shale bed. When this thickness increases, the oat rises accordingly. The oat is connected to a servo-mechanism 17 operatively connected, in turn, to the plate 13. Thus when the flo-at rises, lthe servo-mechanism 17 is operative to decrease the angle of the plate 13, with respect to the horizontal, to discharge more shale. When the thickness of the shale bed decreases, the float 16 drops and the plate 13 is pivoted upwardly -by .fthe servo-mechanism 17 so that little or no shale is discharged.

Positioned adjacent the opposite end of the screen 2' above the compartment 9 is an identical extraction chamber corresponding prime numerals identifying similar elements. Here, the heavy middlings are separated from the lighter coals, and pass out of the chamber 5 in the manner previously described. The jig 9 has a discharging chute 18 for removing the light coal from the jig 1, which pass over the upper end of the wall 7.

From the foregoing description of the various embodiments of this invention, it is evident that the objects of this invention, together with many practical advantages, are successfully achieved. While preferred embodiments of my invention lhave been described, numerous further modifications may be made without departing from the scope of this invention.

Therefore, it is to be understood that .all mat-ters herein set forth or shown in the accompanying drawing are to be interpreted in an illustrative, and not in la limiting sense.

What is claimed:

1. In a jig washer containing liquid and provided with atop screen, downwardly facing pulsating means for causing pulsations of the liquid in the jig washer and thereby causing the separating of material charged to the top screen into a light fraction and a heavy fraction, and means for discharging from the top screen the light fraction which has been separated from the heavy fraction, the improvement comprising providing said jig washer with a downwardly extending extraction chamber for receiving said heavy fraction, said extraction chamber being located below an opening in sai-d top screen and Within said jig washer, said extraction chamber having means at the lower end thereof for discharging the heavy fraction from the top screen, said extraction chamber being subject to said pulsations, `said extraction chamber including two side walls and a downwardly inclined stationary bottom plate secured to one of said side walls for supporting the heavy fraction in said extraction chamber, said bottom plate having a lower end and an adjustable plate attached thereto and inclined upwardly therefrom, said adjustable plate being extended substantially beyond the other wall defining the main por-tion of said extraction chamber in a transverse direction thereto so as to leave a discharge opening between said adjustable plate and the lower edge of said other wall to permit the heavy fraction in said extraction chamber to form `a natural slope on said adjustable plate so that the adjustable plate is not subject to the weight of the heavy fraction in said extraction chamber, said adjustable plate thereby being responsive to small forces for controlling the disch-arge of the heavy fraction from the extraction -chamber and into the jig washer below the top screen.

2. A jig washer according to claim 1 wherein said adjustable plate is perforated.

3. A jig washer according to claim 1 wherein said adjustable plate is hinged to said bottom plate.

4. A jig washer according to claim 1 including means responsive to the thickness of material on the screen to vary the inclination of said adjustable pla-te.

5. In a jig washer for separating material into a light fraction and a heavy fraction, said jig washer having a stationary top screen and means for discharging from the top screen the light and heavy fractions which have been separated, the improvement comprising providing an extraction chamber for receiving particles of the heavy fraction, said extraction chamber being located within said j-ig washer and having means at :the bottom thereof for discharging the heavy fraction from the top screen, said extraction chamber having a first wall attached to said means for discharging and a wall opposite said first Wall, a downwardly inclined stationary bottom plate attached to said opposite wall and an adjustable plate attached to the lower end of said bottom plate and inclined upwardly so as to extend beyond said `fir-st Wall yand leave a discharge opening between said adjustable plate and the lower edge of said first wall to provide a natural slope formation of particles of the heavy fraction on said adjustable plate and thereby permit small forces to control the discharge of the heavy fraction from the extraction chamber.

References Cited by the Examiner UNITED STATES PATENTS 747,214 12/1903 Parker 209-495 1,360,116 11/1920 King 209-457 2,253,760 8/1941 Burnett 209-496 2,275,849 3/ 1942 Fraser 209-484 2,851,160 9/1958 Ore 209-494 HARRY B. THORNTON, Primary Examiner.

HERBERT L. MARTIN, ROBERT A. OLEARY,

Examiners. 

1. IN A JIG WASHER CONTAINING LIQUID AND PROVIDED WITH A TOP SCREEN, DOWNWARDLY FACING PULSATING MEANS FOR CAUSING PULSATIONS OF THE LIQUID IN THE JIG WASHER AND THEREBY CAUSING THE SEPARATING OF MATERIAL CHARGED TO THE TOP SCREEN INTO A LIGHT FRACTION AND A HEAVY FRACTION, AND MEANS FOR DISCHARGING FROM THE TOP SCREEN THE LIGHT FRACTION WHICH HAS BEEN SEPARATED FROM THE HEAVY FRACTION, THE IMPROVEMENT COMPRISING PROVIDING SAID JIG WASHER WITH A DOWNWARDLY EXTENDING EXTRACTION CHAMBER FOR RECEIVING SAID HEAVY FRACTION, SAID EXTRACTION CHAMBER BEING LOCATED BELOW AN OPENING IN SAID TOP SCREEN AND WITHIN SAID JIG WASHER, SAID EXTRACTION CHAMBER HAVING MEANS AT THE LOWER END THEREOF FOR DISCHARGING THE HEAVY FRACTION FROM THE TOP SCREEN, SAID EXTRACTION CHAMBER BEING SUBJECT TO SAID PULSATIONS SAID EXTRACTION CHAMBER INCLUDING TWO SIDE WALLS AND A DOWNWARDLY INCLINED STATIONARY BOTTOM PLATE SECURED TO ONE OF SAID SIDE WALL FOR SUPPORTING THE HEAVY FRACTION IN SAID EXTRACTION CHAMBER, SAID BOTTOM PLATE HAVING A LOWER END AND AN ADJUSTABLE PLATE ATTACHED THERETO AND INCLINED UPWARDLY THEREFROM, SAID ADJUSTABLE PLATE BEING EXTENDED SUBSTANTIALLY BEYOND THE OTHER WALL DEFINING THE MAIN PORTION OF SAID EXTRACTION CHAMBER IN A TRANSVERSE DIRECTION THERETO SO AS TO LEAVE A DISCHARGE OPENING BETWEEN SAID ADJUSTABLE PLATE AND THE LOWER EDGE TO SAID OTHER WALL TO PERMIT THE HEAVY FRACTION IN SAID EXTRACTION CHAMBER TO FORM A NATURAL SLOPE ON SAID ADJUSTABLE PLATE SO THAT THE ADJUSTABLE PLATE IS NOT SUBJECT TO THE WEIGHT OF THE HEAVY FRACTION IN SAID EXTRACTION CHAMBER, SAID ADJUSTABLE PLATE THEREBY BEING RESPONSIVE TO SMALL FORCES FOR CONTROLLING THE DISCHARGE OF THE HEAVY FRACTION FROM THE EXTRACTION CHAMBER AND INTO THE JIG WASHER BELOW THE TOP SCREEN. 